sudo-rs in a clean chroot isn't behaving properly

[sylvestre]

with a new chroot, sudo-rs is doing some unexpected thing.

$ /root/.cargo/bin/sudo --version
sudo-rs 0.2.1

$ /root/.cargo/bin/sudo ls
sudo-rs: cannot execute '/usr/bin/ls': No such device (os error 19)

1. create a chroot
2. cargo install sudo-rs
3. Create a sudoer file
4. /root/.cargo/bin/sudo ls

Defaults        env_reset
Defaults        mail_badpass
Defaults        secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
Defaults        env_keep+="DEB_* BUILD* PATH OTHERMIRROR EXTRAPACKAGES"
# Host alias specification

# User alias specification

# Cmnd alias specification

# User privilege specification
root    ALL=(ALL:ALL) ALL

# Allow members of group sudo to execute any command
%sudo   ALL=(ALL:ALL) ALL

[squell]

After some digging, this seems related to the use_pty behaviour, which is the default for sudo-rs.

If you put Defaults !use_pty in /etc/sudoers (in the chroot), sudo-rs does work as you expect. On the other hand, if you use Defaults use_pty, you get the same problem with original sudo (although a slightly better error message):

# sudo ls
sudo: unable to allocate pty: No such device

I.e. this seems not really a bug but more an issue of the chroot environment being too limited for both sudo and sudo-rs to safely perform their intended function.

[rnijveld]

Specifically it appears that /dev/ptmx is not the proper pseudo terminal multiplexer device that it is supposed to be when using debootstrap, it might be a bug in the way debootstrap sets up the chroot.